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3-Year-Old with Persistent Neck Swelling Despite Antibiotic Therapy
This case features a 3-year-old presenting with persistent neck swelling despite antibiotic therapy, ultimately diagnosed with Mycobacterium avium cervical lymphadenitis.
Imaging overview:
Axial contrast-enhanced CT at two levels demonstrates unilateral cervical lymphadenopathy with central cystic or necrotic change and relatively mild adjacent soft tissue inflammatory change. The lack of significant surrounding cellulitis and the failure to respond to standard antibiotic therapy are important clinical and imaging clues pointing away from typical bacterial lymphadenitis toward a mycobacterial etiology.
Clinical insight:
Mycobacterium avium complex is the most common cause of nontuberculous mycobacterial cervical lymphadenitis in children, most frequently affecting those under 5 years of age and immunosuppressed patients. On imaging, the characteristic appearance is unilateral cervical lymphadenopathy with central cystic change and relatively mild perilandular inflammation, in contrast to the more florid surrounding cellulitis typical of bacterial adenitis. Failure to respond to a standard course of antibiotic therapy is a key clinical indicator that should prompt consideration of mycobacterial infection. Affected nodes can fistulize to the skin surface if left untreated. Surgical excision is often required for definitive management.
Case courtesy of Alexandra Foust, DO, Vanderbilt University Medical Center.